The lead-in-water scandal that disrupted summer for many Hongkongers last year has been blamed on “buck-passing” by a new report this week. Investigators urged the government to retest drinking water at all the city’s ­public housing estates.

Four senior government officials – housing chief Professor ­Anthony Cheung Bing-leung, ­development minister Paul Chan Mo-po, Director of Housing ­Stanley Ying Yiu-hong and Director of Water Supplies Enoch Lam Tin-sing – apologised for what the inquiry called a “collective failure” to prevent the ­scandal. The government spent HK$100 million and months trying to fix the problem.

Eleven public housing estates were found to have drinking water with a lead level of more than 10 ­micrograms per litre – the maximum recommended by the World Health ­Organisation. But Chief Secretary Carrie Lam Cheng Yuet-ngor did not apologise, insisting she had done her duty and saw no intentional breach of rules on the government’s part.

The commission, led by a High Court judge, said leaded solder in the pipes had directly caused the contamination, even though,on paper, the Housing Authority, Water Supplies Department,their contractors and plumbers were all supposed to use lead-free solder.

“This multi-barrier checking system turned out to be no more than a paper system, resulting in a classic case of buck-passing,” the report concluded.